The invention relates to a process for injecting metal-oxide-containing fine particles into a reducing gas, as well as to an arrangement for carrying out the process.
The process of introducing fine ore particles into a reducing gas duct and of reducing the ore particles during transport in the reducing gas duct is known (JP-A-62-164569). According to JP-A-62-164569, the fine ore is sucked into the reducing gas stream via a nozzle. Herein, the problem arises that the reducing gas cannot come into optimum contact with the individual metal-oxide-containing fine particles.
The fine particles entering the reducing gas stream form a compact material stream even if they are injected into the reducing gas stream by means of a carrier gas. Only after a certain distance has been covered is the material stream fanned so that only a smaller distance and, thus, only less time is available for reduction. Another disadvantage is that the material stream, due to its compactness resulting from its entering the space accommodating the reducing gas, may cause wearing of the wall delimiting said space by abrasion.
The object of the invention is to avoid these disadvantages and difficulties and to solve the technical problem of creating a process of the type described above as well as an arrangement for carrying out the process allowing to ensure an optimum contact of the individual fine particles with the reducing gas immediately after the metal-oxide-containing fine particles have entered a space accommodating the reducing gas so that each fine particle is enclosed by reducing gas, immediately after exiting the duct feeding the fine particles. This is to enable the chemical, physical and thermal reactions, which all take place starting from the surfaces of the fine particles, to proceed immediately after introduction of the fine particles into the space accommodating the reducing gas so that the time during which the fine particles are staying in this space can be optimally used. This is also to allow a minimization of the arrangement for direct reduction and an optimum utilization of the reducing gas.